November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

Table A1. Assessment steps1. Do a preliminaryinvestigation2. Determineexisting noiselevelsVisit site or rely on existing knowledge to determine whether traffic is the dominantsource of noise and whether the existing industrial noise sources can be heard overhigh traffic levels for three assessment periods.Take sample measurements to determine whether the existing traffic noise level islikely to be more than 10 dB above the acceptable noise level (ANL—see Table 2.1)in each assessment period.Record at least one week’s worth of continuous valid data covering the period ofoperation of the proposed development. Monitor both the L A90,15 minuteand L Aeq,15 minutelevels. Although the measurement of L A90,15 minutelevels may include traffic, themeasurement of existing L Aeq,15 minutelevels may exclude traffic and other non-industrialsources, except where traffic noise levels are more than 10 dB above the ANL.1. Where existing traffic noise levels ≥ 10 dB above the ANL and existingstationary noise sources are inaudible due to traffic noise:• measure the L Aeq, period(traffic)2. Where existing traffic noise levels < 10 dB above the ANL:• measure the existing L Aeq, periodnoise levels of industrial noise sources at thelocation potentially affected by noise from the new source. To isolate theindustrial contributions to the noise levels from road traffic noise, measurein a different location or calculate the contribution as outlined in Sections3.2 and 3.2.1.3. Measure the background L A90,15 minutelevels so that the intrusiveness criterion canbe determined.4. Determineproject-specificnoise levels5. Predict noiselevels from thesource6. Compare withproject- specificnoise levelsFrom the monitored data, determine single-figure values representing thebackground noise (RBL) and the existing L Aeq,periodlevels, using the methods outlinedin Sections 3.1 and 3.2 respectively. (Note in case (1) traffic noise levels areincluded in the L Aeq, period, whereas in case (2) traffic noise levels may be excluded.)In all cases both the intrusiveness and amenity criteria should be assessed (Section2), however for case 1 (high traffic noise) the high traffic ‘L Aeq, period(traffic)–10 dB’ criterion(Section 2.2.3) replaces the amenity criterion.The project-specific noise levels are the most stringent of the intrusive or amenitycriteria.Investigate the potential for inversion effects as described in Section 5. Noise-levelpredictions should include inversion and wind conditions where the effects of theseare expected to be significant.If the noise source is expected to contain annoying characteristics, applyadjustments to the predicted noise levels from the source as outlined in Section 4.The prediction should take the form of the descriptor used in the project- specificnoise levels.If the predicted noise levels exceed the project-specific noise levels, the proposeddevelopment is likely to have a noise impact on nearby sensitive receivers.NSW industrial noise policy61